In the household appliance industry, heat pump systems have been used for a long time in refrigerators and freezers to cool food, and the industry has driven the development of small, high-quality, low-price heat pump components. In the last few decades, heat pump systems have been introduced in other household appliances, with the express purpose of reducing electricity consumption. Heat pump tumble dryers have been on the market since 2000 and dominate the market today. A heat pump dishwasher was introduced on the market in 2014 and a heat pump washing machine in 2016. The purpose of adding a heat pump system in these three products was to decrease electricity consumption.

Papers I and II used a methodology where transient simulation models were developed and used to increase knowledge about how to decrease electricity consumption for a tumble dryer and a dishwasher by adding a heat pump system. Papers II to V showed that a lower electricity consumption and lower global warming potential together with an energy-efficient drying method, where no humid air evacuates to the kitchen, give a heat pump dishwasher competitive advantages compared to any conventional dishwasher currently on the market. Using simulations, this dissertation concludes that a future commercial heat pump dishwasher, using R600a as a refrigerant, will reduce electricity consumption and total equivalent warming impact (TEWI) by 50% compared to the conventional dishwasher.

The willingness from the customer chain to pay extra for this heat pump dishwasher is because of the decreases electricity consumption and the fact that no humid air evacuates to the kitchen. This willingness makes the heat pump dishwasher to a variant which have possibility to succeed on the future market.

The challenge for the manufacturer is to develop and produce a high-quality heat pump dishwasher with low electricity consumption, predict future willingness to pay for it, and launch it on the market at the right moment with the right promotion in order to succeed.

The competition in the household appliances industry is strong. Manufacturers are continuously trying to develop, produce and sell product functions and features with good profit. To continually develop new features that the customer chain is willing to pay for is a key factor for a manufacturer to survive.

In this study has a heat pump system been added as a new feature to a dishwasher. The first heat pump dishwasher was introduced on the market in 2014 and the heat pump system was only used to heat the dishwasher. Comparing that first heat pump dishwasher was a new closed drying method introduced in this study where no humid air evacuates to the kitchen. Experiments and simulations showed that a dishwasher with an added heat pump system can decrease the total electricity consumption by 50% when cleaning and drying the dishware comparing to an on market conventional dishwasher.

The willingness from the customer chain to pay extra for this heat pump dishwasher is because of the decreases in electricity consumption and the fact that no humid air evacuates to the kitchen. This willingness makes the heat pump dishwasher to a variant which have possibility to succeed on the future market.